This description relates to dynamically loading graph-based computations. Complex computations can often be expressed as a data flow through a directed graph (called a “dataflow graph”), with components of the computation being associated with the vertices of the graph and data flows between the components corresponding to links (arcs, edges) of the graph. The components can include data processing components that receive data at one or more input ports, process the data, and provide data from one or more output ports, and dataset components that act as a source or sink of the data flows. A system that implements such graph-based computations is described in U.S. Pat. No. 5,966,072, EXECUTING COMPUTATIONS EXPRESSED AS GRAPHS.